How devtools map minified JS code back to your TypeScript source code(www.polarsignals.com)
103 pointsby manojvivek2 days ago4 comments
  • pseufaux20 hours ago
    Recent related post where Apple seemingly forgot to disable source maps for the App Store

    Apple's App Store Full Front End Source Code

    https://news.ycombinator.com/item?id=45804664

    edit: formatting

  • kaysona day ago
    I love it when things are displayed so nicely on mobile. This could've been a pain to read and get through but it was actually quite pleasant.
  • tantalor2 days ago
    > Notice how the decoded values give relative positions, each value represents the difference from the previous position, not absolute coordinates. This is crucial: instead of encoding large column numbers like 27698 in minified files, source maps only store small deltas like +7 or +15, making the encoded strings much more compact.

    Wouldn't "offset" be a more apt term?

    • manojvivek2 days ago
      To me, “offset” sounds more like the distance from the start, whereas here the values are relative to the previous segment. Not a native english speaker, so I could be wrong.
      • tantalor2 days ago
        Offset is difference from a starting point or a previous position
        • jagged-chisel2 days ago
          “Offset” is not enough on its own. Offset from what? Start of file? Absolute offset. Previous offset? Relative offset.
          • willrshansen2 days ago
            2nd order offset. The offset from the <offset from the start of the file>
    • hanikesn2 days ago
      Delta Encoding is the common term
      • tracker1a day ago
        Agreed... Delta Encoding, or even Delta Offset would work together.
    • accrual2 days ago
      In this case I feel it's like six of one and a half-dozen of the other.

      Delta definition 4: (mathematics, physics, engineering) The symbol Δ; A change in a quantity, likely from "d" for "difference"

      Offset definition 7: The distance by which one thing is out of alignment with another.

      Got these from Wiktionary:

      * https://en.wiktionary.org/wiki/delta

      * https://en.wiktionary.org/wiki/offset

    • recursive2 days ago
      It sounds equally apt to my ear. I've used both words for this concept in the past.
    • 2 days ago
      undefined
    • paulddraper2 days ago
      Delta and offset mean the same thing — the difference between two amounts.

      Delta is perhaps slightly more obscure outside of a math setting. Perhaps.

      • saghma day ago
        I feel like choosing the synonym that happens to be one letter shorter when the operation is literally intended to track things in a way that's more conscise is about as "apt" as it could be!
  • zb32 days ago
    Tangentially related, but last year I've made a tool to recover original sources from web apps which expose source maps (with the sourcesContent value present), including enumerating all lazily loaded chunks:

    https://github.com/zb3/getfrontend